Balanced valve structure



1944. c. A. FRISCHE 2,362,476

BALANCED VALVE STRUCTURE I Original Filed Oct. 19, 1940 |NLET INLET FROM OUTLET FROM PUMP SUMP PUMP INVENTOR. CAR L A. FRISCHE JAMz AW HIS ATTORNEY Patented Nov. 14,1944

amncsn VALVE s'rnucruas Carl A. Frische, Great Neck, N. Y., assignor to Sperry Gyroscope Company, Inc., Brooklyn, N. Y.. a corporation of New York Original application October 19, 1940, Serial No.-

361,860. Divided and this 1943, Serial No. $91,103 H v 7 Claims. (CL 251-20) The present divisional application is based on the balanced valve sublect matter shown and.

described in the parent case, flled October 19, 1940, Serial No. 361,860 by Carl A. Frische and Orland E. Esval, for an improvement in Servo mechanisms.

This invention relates to i a balanced valve structure. 7 v

v The structural details of the invention will be apparent from the following description when read in relation to the accompanying drawing in which the single view shown is a vertical section taken through the improved valve.

Pipes i4 and it provide inlet connections for the valve body it. Fluid is supplied to the two inlet openings in the valve body It by way of the pipes I4 and II from suitable pumps (not shown). As illustrated. the valve has an operating lever or controlling member l'l pivoted at It by which valve pistons 20 and 20' are differentially controlled. Closed end cylinders IS and it are provided in the valve body for receiving the respective pistons therein. The pistons project beyond application June 11,

the taper oi the valve body adjacent thereto,

then the lower ends or heads-of the valve pistons and 20' may be tapered at an angle of- 45 with respect to the piston axis.

The inlet to ducts II. is located at a point in the valve intermediate the entrance of fluid to the valve and the exit of fluid therefrom, the exact positioning of the same serving to determine the back pressure to be exerted on top I velocity of fluid flow. will be greatest at the the open end of the cylinders in which they are slidably mounted and cooperate with the adjacent respective nipples or valve seats 2i and 2 i The pistons do not actually close down upon their respective seats, so that there is a continuous flow oi fluid frompipes i4 and i5 through the seats, past the valve pistons through common outlet passage in the valve body into the outlet or sump pipe 23.

In accordance with the teaching of the present invention, each oi the valve pistons 20 and 20' are substantially balanced. In this connection, the fluid pressure required is applied against the inner wall of the valve pistons by way of the respective ducts 25 and 25', channels 26 and 26, and ducts 21 and 21'. The last noted ducts lead to the respective cylinders i8 and it at the closed end thereof.-

The heads of the valve pistons cooperating with the adjacent valve seats are conically tapered. The seat forming portion of the valve body is also conically tapered. The seat forming nipples 2i and ti and the adjacent surrounding walls of the valve body are tapered as designated at 29 and 29'. It will also be noted that the heads of the valve pistons 29 and 20' are tapered at adifierent'angle than the uniform taper of the nipples and the adjacent portion of the valve body thereto. Thus, if the upper ends of the seats or nipples 2i and 2! are tapered at an angle of 30 with respect to the piston axis,.i. e.,

' subtend an angle of 60", which is alsotrue of valve body with inlet and outlet openings and o periphery of the valve piston head and the least at the center. By the Bemouilli principle of hydrodynamics, this results in a decreased pres sure at the periphery of the valve so that the average pressure on the valve piston head is lower than the pressure in the corresponding fluid inlet pipe. If the duct 25 or 25 were to transmit-the pressure oithe inlet pipes to the rear of either of the valve pistons, one of the individual valves would be drawn closed. However, a pressure gradient exists through the annular passages and the ducts 25, 25' are tapped off at a point suitable for obtaining proper pressure in the closed end of the respective valve cylinders to substantially balance the average pressure applied to the respective piston heads.

The back pressure obtained will always be slightly less than or, at most. equal to the average pressure on the piston heads despite the various conditions of fluid flow through the individual valves above description or shown inthe accompanying drawing shall be interpreted sis-illustrative andnot in a limiting sense.

What is claimed is: f

1. A fluid controlling balanced valve having a 'ticned in said body, an annular passage between said seat and said head through which fluid flows in passing from the inlet to the outlet openings,

- a duct connecting anintermediate point or said ssage with the rear 01' the valve piston, and means for moving said valve piston.

2. A valve oi the character claimed in claim 1, in which the conical seat has an angle of taper less than that oi. the head of the piston.

3. A valve of the character claimed in claim 1, in which the angle 0! taper of the seat is 30", and the angle of taper of the head or the valve piston is 45.

4. A balanced valve comprising a valve body having aclosed end-cylinder formed therein, a valve piston slidably mounted in said cylinder having one end thereot projecting exteriorly of the cylinder, a valve seat in the body for the proiecting end of the piston, the adjacent surfaces oi the Piston and seat defining a fluid throttling passage therebetween, a duct connecting assure the closed end of the cylinder with a point in said passage. and means for moving said valve piston.

'5. A balanced valve having a tapered seat and a valve piston whose seat cooperating end is tapered at an angle diflerent than the angle of taper of the seat, the adjacent annular suriaces of the seat and piston defining a fluid throttling passage, a duct connecting the opposite end of the valve piston with'a point in the passage, and means for controlling said valve piston.

6. A fluid-controlling valve comprising a valve body having a closed end cylinder formed therein, a valve piston movable in said cylinder having one end thereof projecting exteriorly of the cylinder, a valve seat in the body for the projecting end of the piston. the adjacent surfaces of the piston and seat defining a fluid throttling passage therebetween, and a duct connecting the closed end of the cylinder with a point in said passage.

. '7. A valve of the character claimed in claim 6, in which said duct is formed in the valve body.

CARL A. FRISCHE. 

